foo.cpp: In function 'void init()':
foo.cpp:43:6: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  if(m<adj[1].size()) {printf("-1"); exit(0); }
      ^
foo.cpp:49:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0,v,w;i<adj[now].size();++i,++c) {
                    ^
foo.cpp: In function 'bool check(ll)':
foo.cpp:83:10: error: 'dfs' was not declared in this scope
  if(dfs(1)) return true;
          ^
foo.cpp:86:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0,v;i<adj[1].size();++i) {
                  ^
foo.cpp: In function 'bool dfs(int)':
foo.cpp:110:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0,v;i<adj[u].size();++i) {
                 ^
foo.cpp: In function 'int main()':
foo.cpp:126:17: warning: unknown conversion type character 'l' in format [-Wformat=]
  printf("%lld",R);
                 ^
foo.cpp:126:17: warning: too many arguments for format [-Wformat-extra-args]
foo.cpp: In function 'bool check(ll)':
foo.cpp:104:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^